U.S. Pat. No. 3,848,912 discloses a latch assembly for a railway hatch cover. A handle actuates a latch which is guided in movement between open and closed positions by a slot in a mounting flange. This concept requires an L-shaped slot in the locking member which is engaged by a protrusion in the handle.
In U.S. Pat. No. 3,325,200 a handle is rotated to rotate a locking member between engaged and disengaged positions. A stud located on the locking member extends into a slot in a U-shaped extension of the handle and rotation of the handle translates rotative movement to the locking member. The locking member pivots about a separate axis from the handle such that a given rotation of the handle results in a greater rotation of the locking member.